The researchers involved in this study had as objective to determine and compare the concentrations of metals in yerba mate (Ilex paraguariensis) marketed and consumed in the different states of southern Brazil. Previous research had already detected the presence of many vitamins and metals in yerba mate from the mineral composition of the plant itself or the contamination of water resources by the use of fertilizers, pesticides, coal and oil combustion, incineration of urban and industrial waste, among other processes. In this study “Arsenic, cadmium and lead concentrations in Yerba mate commercialized in Southern Brazil by inductively coupled plasma mass spectrometry”, published in Ciência Rural (Vol. 47, No. 12), the researchers tested 104 samples collected at supermarkets in the states of Paraná, Santa Catarina and Rio Grande do Sul, determining the concentration levels of arsenic, cadmium and lead metals by using inductively coupled plasma mass spectrometry (ICP-MS), model Nexion 300D (Perkin Elmer). The research was based on previous studies on toxic metals in yerba mate, such as Saidelles et.al. (2009; 2013) and Ernst (2002) on Asian herbs.

According to the results, the yerba mate samples show contamination by cadmium and lead. The concentration of cadmium was higher than the limit established by ANVISA in 84% of samples from Rio Grande do Sul, 63% from Paraná samples and 75% from samples from Santa Catarina. Even so, the concentration of these metals in the infusion is low.

The researcher Lisia Maria Gobbo dos Santos comments that the study provides important information to assist the competent bodies in assessing the maximum value of metals allowed for these products. The large number of samples from different states and brands of yerba mate, covering almost 80% of the brands available in the market, allowed the researchers to have an overview of the concentration of metals in a much consumed product in the southern region of the country. According to Lisia, the likelihood of risk related to the consumption of these infusions needs to be elucidated by other researches, consolidating the knowledge about yerba mate.